Systems that handle, process or use electric wave energy are composed of subsystems, subassemblies and components that may be made by various different manufacturers, to specifications imposed by others, and under conditions requiring not only that the specifications be met, but also that they be met economically and repeatedly from one manufacturing run to another. Particularly in the very high frequency regions and above, for example the microwave area around 1.0 GH.sub.z, these requirements present a challenge that is not readily met with techniques that are generally available. As one example, a device that is designed to accept an input wave from which it presents at several outputs components of that wave bearing prescribed different phase relations to each other may be most conveniently and economically realized using diode phase shifters cooperating with a TEM-mode transmission line net of the strip-transmission line variety, the whole being enclosed in an electrically-conductive case for physical strength and electrical shielding. Each component and subassembly of this device will present its own design problems.
While the TEM-mode line net may propagate the useful wave energy in the desired frequency band, the enclosure may support other modes, known sometimes as "box resonance modes" that sap energy from the useful energy and degrade operation of the device. The TEM-mode line itself has to be handled in a way that will preserve its balance and avoid the setting up of fields which could induce such "other mode" energy into the enclosure. The enclosure and the TEM-mode line structure must be assembled in a way that assures minimum physical distortion of the line structure, and maintains its dimensional stability not only throughout each device, but also from one device to the next. At the same time, the enclosure should be designed to discourage the presence in it of box resonance modes of wave energy. The phase shift at each terminal must be set to the performance specification reliably, and preferably in a way that will not require any degree of disassembly of the device in order to make final or trim adjustments after the device has been assembled. The assembly technique must, in addition to taking into account all of the above-mentioned considerations, be inexpensive in both the materials and the labor that are used. These requirements and desired results are applicable, with necessary changes in particulars, to a wide variety of electric wave propagating and supporting devices.